数据结构：双向链表2

/************************************************************************/

/* 数据结构：双向链表                                                                               */

/* 挑灯看剑-shuchangs@126.com 2010-10                                                             */

/* 云歌国际（Cloud Singers International） www.cocoral.com                          */

/************************************************************************/

//以上接上一版面 《数据结构：双向链表1》

 

/*

* 打印链表函数，输入参数为链表头元和打印标

* （tag='H'正向打印，tag='T'反向打印）

*/

void NodePrint(NodeHead H, char tag)

{

       static Status NodeIsEmpty(NodeHead H);//函数原型

       NodePointer p = NULL;

       COUNT i = 1;

       COUNT n = H.len;

       printf("线性链表长度：%d\n", n);

       if (!NodeIsEmpty(H)) //如果线性链表非空

       {

              switch (tag)

              {

              case 'H':

                     p = H.head;

                     puts("正向打印结点信息：");

                     for (i = 1; i <= n; i++)

                     {

                            printf("Node[%d] = %d\n", i, p->data);

                            p = p->next;

                     }

                     break;

              case 'h':

                     p = H.head;

                     puts("正向打印结点信息：");

                     for (i = 1; i <= n; i++)

                     {

                            printf("Node[%d] = %d\n", i, p->data);

                            p = p->next;

                     }

                     break;

              case 'T':

                     p = H.tail;

                     puts("反向打印结点信息：");

                     for (i = n; i >= 1; i--)

                     {

                            printf("Node[%d] = %d\n", i, p->data);

                            p = p->prior;

                     }

                     break;

              case 't':

                     p = H.tail;

                     puts("反向打印结点信息：");

                     for (i = n; i >= 1; i--)

                     {

                            printf("Node[%d] = %d\n", i, p->data);

                            p = p->prior;

                     }

                     break;

              default:

                     puts("打印失败！");

                     break;

              }

       }

       else //如果线性链表为空表

       {

              puts("打印失败！线性链表为空表！");

       }

}

 

void autoList(NodeHead* H, int n)

{

       //自动生成n个结点的线性链表

       NodePointer p = H->head;

       int i = 1;

       for (; i <= n; i++)

       {

              NodeInsert(H, i, i * 2);

       }

       //NodePrint(*H,'H');

}

 

//删除线性链表中第i个位置结点，并用LNode型结点返回之

Status NodeDelete(NodeHead* H, int i, Node* N)

{

       Status status = ERROR;

       NodePointer p = NULL, q = NULL;

       COUNT j = 0, n = H->len;

       //判断是否是空表

       if (!NodeIsEmpty(*H))

       {

              if (i == 1)

              {

                     //如果i==1

                     p = H->head; //头结点（第一个结点）

                     q = p->next; //次头结点

                     H->head = q;   //修改后继结点

                     q->prior = NULL; //修改前驱结点

 

                     N->data = p->data; //返回结点信息

                     N->prior = p->prior;

                     N->next = p->next;

 

                     free(p);

                     H->len -= 1; //长度减1

                     status = OK;

                     puts("删除成功！");

              }

              else if (i >= 2 && i <= H->len - 1)

              {

                     //如果i在区间2-LEN-1之间

                     //先查找i-1个结点

                     for (p = H->head,j = 2; j <= i - 1; j++)

                            p = p->next; //p前进一位

                     //进行删除操作

                     q = p->next; //指向删除结点

                     p->next = q->next;

                     q->next->prior = p;

 

                     N->data = q->data; //返回结点信息

                     N->next = q->next;

                     N->prior = q->prior;

 

                     free(q);

                     H->len -= 1; //长度减1

                     status = OK;

                     puts("删除成功！");

              }

              else if (i == H->len)

              {

                     //如果删除位置是最后一个结点

                     q = H->tail; //尾结点

                     p = q->prior; //次尾结点

 

                     H->tail = p;

                     p->next = NULL;

 

                     N->data = q->data; //返回结点信息

                     N->next = q->next;

                     N->prior = q->prior;

 

                     H->len -= 1; //长度减1

                     status = OK;

                     free(q);

                     puts("删除成功！");

              }

              else

              {

                           status = ERROR;

                     printf("删除失败！链表区间为：1-%d,删除位置为：%d 越界！\n",

                            H->len, i);

              }

       }

       else

       {

              status = ERROR;

              puts("删除失败！链表为空表！");

       }

 

       return status;

}